Freeport-McMoRan’s (NYSE:FCX) Arizona copper smelter will remain closed for several weeks following fires caused by molten copper at the facility, according to Reuters. Being Freeport’s only US copper smelter, the shutdown could raise concerns regarding refined copper supplies in the country.

As quoted in the publication:

Freeport is considering sending concentrates to other smelters while repairs are underway. The company’s other smelter, Atlantic Copper, is in Spain.

A prolonged shutdown would raise concerns about supplies in the U.S. market of refined copper as Rio Tinto’s big smelter in Utah struggles with low ore grades.

The shutdown comes at a critical time for the industry as companies that use copper to make wire and plumbing hammer out terms of next year’s supply contracts.